[codesushi42]

True. But a methane based lifeform would be radically different than the carbon based lifeforms found on Earth, and would have emerged separately.

[dredmorbius]

Oddly, that wasn't your claim.

[codesushi42]

It was. Read the OP's claims about Mars.

Mars alone does not provide the answer about whether or not life evolved independently in our solar system.

[hdfbdtbcdg]

Can you elaborate?

[codesushi42]

They would not have cell membranes with phospholipids for one thing.

[hdfbdtbcdg]

Why not? Methane is a hydrocarbon. We are made of hydrocarbons.

I just can't understand what the chemical difference is. Are these differences because of oxygen? I.e. life forms of C+H vs lifeforms of C+H+O?

[codesushi42]

Yes. Phospholipids are not viable outside of water; they would not be strong enough to perform well in liquid methane.

[hdfbdtbcdg]

So the suggestion is carbon based biology at very reducing conditions?

What temperatures are we considering?

[codesushi42]

Cold. Methane becomes liquid at -161.6C.

It is not my suggestion. It's suggested by scientists that Titan may host methane based life.